Stub puller and method of forming the same



Dec. 29, 1936. L. L. ZIHLER 2,066,132

STUB FULLER AND METHOD OF F ORMING THE SAME F'iled Nov. 5, 193.5

I NVENIVLOR ATTORNEY Patented Dec. 29, 1936 srs T FFEE STUB FULLER AND METHOD OF FORMING THE SAME 2 Claims.

This invention relates to a stub extractor and method of forming the same and more particularly to an improvement on the form of stub extractor described in my United States Patent No.

1,108,059, dated August 18, 1914.

The stub extractor forming the subject of the present invention is primarily designed for the removal of broken ends of pipe or other objects which are open in the center or which can be open in the center to permit of the insertion of the extractor. With pipe fittings it frequently happens that a pipe is broken off close to a fitting and the pipe stem is so short that wrenches, pliers or other tools are inadequate for the removal of the stub. To remove such threaded stubs the present extractor is inserted in the end of the stub and turned until its spiral threads engage the stub and cause it to turn, thereby unscrewing the stub from the fitting. This fre- 0 quently avoids the necessity of removing a large amount of piping in order to remove and replace the fitting when the stub could not be removed.

In cutting pipe a burr is formed at the cut ends of the pipe which very often is not removed. This burr frequently interferes with the insertion of stub extractors, such as are shown in my aforementioned patent and it is necessary to ream out the burr before the extractor can be engaged with the stub. It is the principal object of the present invention to provide such a stub extractor in which the inner end is formed so that it will ream out such a burr, if encountered, and permit the threads of the stub extractor to take hold.

It is another object of the present invention to provide such a stub extractor having threads of increased pitch so that they are sharper and will more quickly and positively engage the stub without danger of expanding the stub so as to render its removal more difficult.

In the accompanying drawing:

Fig. 1 is a perspective view of a blank forging from which I manufacture my stub extractor.

Fig. 2 is a similar view showing the completed stub extractor.

Fig. 3 is a side elevation of the completed stub extractor, shown in Fig. 2.

Fig. 4 is an end elevation of the blank shown in Fig. 1.

As illustrated in Fig. 1, the material from which my stub extractor is fashioned comprises a blank l0 which is preferably made of forged steel and includes a short shank element I I, a tapering intermediate section l2 and a tip l3. The shank element ll is preferably square in cross section (olive-101) and the intermediate tapered portion I2 is four sided, terminating in corner edges which form continuations of the corners of the shank element H. The tip I3 is also four sided and its corners form continuations of the corners of the intermediate section 82. In forging the blank the four faces of the intermediate section H3 are formed to provide rounding recesses M which extend from corner to corner, and the four side faces of the tip 13 are likewise formed to provide 10 rounding recesses l5 extending from corner to corner of the tip.

Having provided a blank as illustrated in Fig. 1 I place the blank in a furnace or oven and bring it to a cherry red heat, whereupon the blank 15 is removed from the oven and the tip l3 thereof is inserted in a clamp or vise so that a rotative movement of the shank element l I will twist the intermediate section, as indicated in Fig. 2, approximately three-quarters of a full turn, with 20 the result that the four sharp margins I6, l1, l8, and IQ of the intermediate section are formed into sharp threads, as indicated in Fig. 2.

The recesses l5 in the tip are preserved during this twisting operation and therefore the tip I3, 2 in the finished product, is provided with sharp corners 20, 2|, 22, and 23 which are designed to act in the capacity of a reamer.

When my stub extractor has been properly cooled following the twisting operations, the stub 30 extractor is complete since no margin of the thread portions shown in Fig. 2 is necessary and no further grinding of the tip I3 is necessary to sharpen its corners and provide a reamer. By indenting the blank during the forging operation 35 it will be necessary that the threads are much sharper than if this were not done and it will also be seen that this recess, in the tip, provides the sharp corners so that the tip can be forced into and ream out any burr in the stub. Since the degree of angle of the threads deviating from the axis of the completed extractor is decidedly obtuse, it will be found that my extractor will engage a broken pipe stub in a T or L pipe fitting and will permit of uncrewing this stub from the 45 fitting.

In imparting a reaming function to the tip 13 it will be seen that the corners of this tip can be ground into the form shown if the sides of the tip are not originally recessed, as shown in Fig. 1. 50

From the foregoing it will be apparent-that the present invention provides a stub extractor in which the tip which is necessary for forming the extractor is utilized as a reamer for removing the burr on the inside of the stub, if it is necessary to 55 do so, and at the same time the threads of the extractor are also provided by the simple expedient of recessing the sides of the tip and the intermediate portion of the blank before it is twisted into its final shape.

I claim as my invention:

1. A device of the character described, comprising a one piece body which is angular in cross section throughout and includes a square shank, a coaxial tapered intermediate portion twisted to form spiral threads adapted to bite into and remove the stub from a pipe fitting and a coaxial tip of reduced size at the reduced end of said tapered intermediate portion, the corners of said tip being arranged to describe a square and extending substantially parallel with the axis of the body and the faces of said tip between said corners curving inwardly toward the axis thereof thereby to form sharp edges of said corners which act to ream out any burrs interfering with the insertion of said intermediate portion into the stub.

2. The method of forming a stub puller of the character described which comprises forging a blank of elongated form and generally square in cross section, the faces and corners of which are continuous from one end of said blank to the other, and having a shank, an intermediate portion of tapering form and a tip projecting outwardly from the small end of said intermediate portion, the four faces of said intermediate portion being recessed from corner to corner and substantially the full length thereof and the four side faces of said tip being likewise recessed from corner to corner to form four sharp edges extending parallel with the axis of the blank and twisting said shank relative to said tip to provide sharp spiral threads on said intermediate portion, said sharp edges providing reaming edges to remove any burrs interfering with the insertion of said intermediate portion into a stub.

LEON L. ZIHLER. 

